Several pages are not shown when create Menu

My website has 5 languages (EN-NL-DE-ES-FR). I had to rewrite the page titles of several existing pages to get a better SEO result.
As example I rewrote a part of it from “my_account” into “customerpanel”. Did this with all 5 pages showing the account page.
In wp-admin/nav-menus.php I do not get the corrected pages to select for the menu.
Even when I search for “kundenpanel” – “panel-de-clientes” – “Klantenpanel” – “Panneau-client” none of the changed pages is shown. When search on “panel” I only get the English page in the list.
When chosing Spanish only the ES front page is shown in the View All listing within Menu.
When using the German Menu I get a lot of English pages + Spanish.
Means in my opinion the menu is a mess.

Question: How can I get the right pages in the menus? Are there tools for it or …?

• This topic was modified 4 years, 4 months ago by RonaldS.